1. Technical Field
The present invention relates to a light source device having a discharge lamp as a light emitting source and a reflection mirror that collects light from the discharge lamp, and a projector using the same.
2. Related Art
An example of a light collection reflector used in an illumination system of a liquid crystal projector or the like is a multi-facet reflector, each facet using, for example, an ellipsoidal surface. When such a multi-facet reflector is used, a large number of light source device images are visibly focused on the illuminated area, causing non-uniformity in illuminance and color. To address such a problem, a light collection reflector has been designed in which it has a reflection surface section shaped into a substantially quadratic surface of revolution with an axis oriented toward the center of the illuminated area and the reflection surface section is divided into sub-reflection surfaces, each of which is adjusted and inclined to the axis (for example, JP-A-9-222580, JP-A-10-50120, and JP-A-2001-242545).
The light collection reflector described above can collect light efficiently and illuminate the intended area with less non-uniformity in illuminance and color. However, since the reflection surface section is circular when viewed from the front and formed of a plurality of surfaces, the optical axis of each of which extends outward, such a light collection reflector has limitations in terms of reduction in its thickness and size. Further, the light collection reflector described above is difficult to manufacture, not easy to ensure the accuracy, and suffers great loss of light.